added negative numbers support

ppaska · ppaska · commit 545ec212d249 · 2020-12-27T14:29:33.000Z
diff --git a/index.html b/index.html
@@ -28,7 +28,7 @@
 <body>
   <div class="container">
     <h4>JSPython development console</h4>
-    <div id="editor">2 == 1/2+1/2 and 1/2+1/2 == 1</div>
+    <div id="editor">x = -3.14 + 1</div>
     <!--
           def f(n):
             n * n
diff --git a/src/interpreter.spec.ts b/src/interpreter.spec.ts
@@ -58,8 +58,8 @@ describe('Interpreter', () => {
 
   it('1*2/4 + 2*3/6', () => {
     expect(e.eval("1*2/4 + 2*3/6")).toBe(1 * 2 / 4 + 2 * 3 / 6)
-    expect(e.eval("1*2/4 + 2*3/6-2.3")).toBe(1 * 2 / 4 + 2 * 3 / 6 - 2.3)
-    expect(e.eval("7+1*2/4 + 2*3/6-2.3")).toBe(7 + 1 * 2 / 4 + 2 * 3 / 6 - 2.3)
+    expect(e.eval("1*2/4 + 2*3/6 - 2.3")).toBe(1 * 2 / 4 + 2 * 3 / 6 - 2.3)
+    expect(e.eval("7+1*2/4 + 2*3/6 - 2.3")).toBe(7 + 1 * 2 / 4 + 2 * 3 / 6 - 2.3)
   });
 
   it('5 – (5 * (32 + 4))', () => {
@@ -329,12 +329,39 @@ describe('Interpreter', () => {
     expect(await e.evaluate('x?.p1?.p != null and x.length >0')).toBe(false)
   });
 
-  it('arithmetic + comparison', async () => {
+  it('arithmetic + comparison', async () => {    
+    expect(await e.evaluate('0.25 == 1/4')).toBe(true)
+    expect(await e.evaluate('0.25 == 1/2')).toBe(false)
+
     expect(await e.evaluate('1+2*3 == 5 or 1 > 3')).toBe(false)
     expect(await e.evaluate('1+2*3 == 5 or 1 < 3')).toBe(true)
 
     expect(await e.evaluate('2 == 1/2 + 1/2 and 1/2 + 1/2 == 1')).toBe(false)
     expect(await e.evaluate('(2 == 1/2 + 1/2) and (1/2 + 1/2 == 1)')).toBe(false)
     expect(await e.evaluate('(2 == (1/2 + 1/2)) and ((1/2 + 1/2) == 1)')).toBe(false)
-  });  
+  });
+
+  it('Negative numbers', async () => {    
+    expect(await e.evaluate('x=-1\nx')).toBe(-1)
+    expect(await e.evaluate('x=-3.14 + 3\nx')).toBe(-3.14 + 3)
+    expect(await e.evaluate('-3.14 - 3')).toBe(-3.14 - 3)
+    expect(await e.evaluate('x=5\nx*-1')).toBe(-5)
+    expect(await e.evaluate(`
+    def f(x):
+      return x
+    
+    f(-5)
+    `)).toBe(-5)
+
+    expect(await e.evaluate(`
+    def f(x):
+      return x
+    
+    f(-0.14)
+    `)).toBe(-0.14)
+
+    expect(await e.evaluate('1/2*-1 == -0.5')).toBe(true)
+
+  });
+
 });
diff --git a/src/parser/parser.spec.ts b/src/parser/parser.spec.ts
@@ -15,7 +15,7 @@ describe('Parser => ', () => {
   });
 
   it('1+2-3', async () => {
-    let ast = new Parser().parse(new Tokenizer().tokenize("1+2-3"))
+    let ast = new Parser().parse(new Tokenizer().tokenize("1 + 2 - 3"))
     expect(ast.body.length).toBe(1);
     expect(ast.body[0].type).toBe("binOp");
     const binOp = ast.body[0] as BinOpNode
diff --git a/src/tokenizer/tokenizer.ts b/src/tokenizer/tokenizer.ts
@@ -1,4 +1,4 @@
-import { Token, TokenTypes } from '../common';
+import { getTokenType, getTokenValue, Token, TokenTypes } from '../common';
 
 const SeparatorsMap: Record<string, string[]> = {
     '\n': ['\n'],
@@ -85,7 +85,7 @@ export class Tokenizer {
             if (symbol == ' ' && this.tokenText.length !== 0) {
                 this.tokenText = this.processToken(this.tokenText, tokens);
                 continue;
-            } else if ((SeparatorsMap[symbol]) && !this.isPartOfNumber(symbol, this.tokenText, this._cursor)) {
+            } else if ((SeparatorsMap[symbol] !== undefined) && !this.isPartOfNumber(symbol, tokens)) {
                 // handle numbers with floating point e.g. 3.14
                 this.tokenText = this.processToken(this.tokenText, tokens);
                 this.tokenText = symbol;
@@ -242,12 +242,12 @@ export class Tokenizer {
         return !isNaN(res) ? res : null;
     }
 
-    private isPartOfNumber(symbol: string, token: string, cursor: number): boolean {
-        // '-' needs to be handled e.g. -3; 2 + -2 etc
-        // if(token.length == 0 && symbol === '-') {
-        //     return true;
-        // }
-        if (symbol === '.' && this.parseNumberOrNull(token)) {
+    private isPartOfNumber(symbol: string, currentTokens: Token[]): boolean {
+        if (symbol === '-' && !this.tokenText.length) {
+            // '-' needs to be handled e.g. -3; 2 + -2 etc
+            const prevToken = (currentTokens.length !== 0)? currentTokens[currentTokens.length - 1] : null;
+            return prevToken === null || (getTokenType(prevToken) === TokenTypes.Operator && getTokenValue(prevToken) !== ')');
+        } else if (symbol === '.' && this.parseNumberOrNull(this.tokenText) !== null) {
             return true;
         }
         return false;
